Method and apparatus for applying fabric lubricant in a sewing machine

ABSTRACT

In a sewing machine, a method and an apparatus wherein an atomized stream of a fabric lubricant is continuously supplied under pressure to either a nozzle to spray a jet of lubricant onto the fabric or a separate reservoir. A valve device switches the stream between the nozzle and the reservoir such that a pressurized stream is readily available as a jet at the nozzle when needed.

United States Patent [72] Inventor Kenneth W. Stretton [56] ReferencesCited r England UNITED STATES PATENTS P 853,874 5/1907 l-ladsell 112/43[22] F1led Dec. 26, 1968 2,316,647 4/1943 112/218 [45] Patented Mar. 9,1971 2,316,648 4/1943 112/218 [73] Ass1gnee Wood, Bastow & CompanyLimited 2 442 222 5/1948 112/43 32] Priority Dec. 30 1967 3 G 81min2,650,557 9/1953 l-lauser 112/218 [3 1 33 A; 3,109,398 11/1963Abramowicz 112/218 [311 3,185,253 5/1965 Lansky 184/55(A) PrimaryExaminer-Jordan Franklin Assistant Examiner-George H. Krizmanich 54METHOD AND APPARATUS FOR APPLYING &

FABRIC LUBRICANT IN A SEWING MACHINE 15 Claims 4 having Figs ABSTRACT:In a sewing machine, a method and an apparatus [52] 0.8. CI 112/218,wherein an atomized stream of a fabric lubricant is continu 112/43 ouslysupplied under pressure to either a nozzle to spray a jet [51] Int. Cl..D05b67l00, of lubricant onto the fabric or a separate reservoir. Avalve D05b 71/04 device switches the stream between the nozzle and thereser- [50] Field of Search 112/256, voir such that a pressurized streamis readily available as a jet 260, 218, 219, 43; 184/55 (A) at thenozzle when needed.

PATENTEDHAR slam 3.568.615

SHEET 2 UF 4 FIG2.

MMTEQE AND APPARATUS lFGll-l APPLYING FABRMI LUBRLQANT EN A @EWHNG MACEThis invention is for improvements in or relating to sewing machines andto methods of using sewing machines. In the manufacture of articles ofclothing from fabrics incorporating an elastic thread problems oftenrise in the sewing together of one or more plies of such fabric. Theproblem arise due to the fact that when the needle of the sewing machineenters the fabric there is a possibility that the point of said needlewill cut into one of the elastic threads forming the fabric. if thishappens the elastic thread normally under tension will tend to run backinto the fabric, it will probably form a hole in the fabric and in anyevent will create an unsightly appearance in the fabric and render thearticle with such a cut thread unacceptahis.

The expression elastic thread as used herein includes both threads madefrom natural and synthetic rubber and those type of threads now known inthe textile trade as elastomeric yarns.

It has also been found that with sewing machines operating at highspeeds, i.e. upwards of 3,500 stitches per minute that frictional forcesoccur as the needle is inserted into and withdrawn from the fabric andas the sewing thread also passes through the fabric to such an extentthat heat is generated and it has been found that this heat damagesyarns made of synthetic plastics material which are susceptible todamage at elevated temperatures. It has been found that in the sewing ofcertain elastic fabrics incorporating elastomeric yarns that needlesoperated at 5,000 stitches per minute generate heat sufficient to meltelastomeric yarns and this also causes holes or other unsightly andunacceptable blemishes to be formed in the fabric. The heat generated athigh sewing speeds will damage all types of fabrics incorporating yarnsliable to damage at elevated temperatures whether they be rubber coveredor elastorneric.

it is an object of the present invention to provide both apparatus and amethod to overcome or minimize this problem.

Accordingly the present invention provides firstly apparatus for usewith sewing machines comprising a source of fabric lubricant and meansfor spraying an atomized jet of lubricant on to the fabric or the needleof the sewing machine immedistely prior to the needle of the sewingmachine entering said fabric. The present invention also provides amethod of sewing fabric particularly but net exclusively thatincorporating elastic yarns which comprises spraying an atomized fabriclubricant on to thefabric or to the needle immediately prior to theneedle entering said fabric.

The present invention provides apparatus for use with a sewing machineand with a source of compressed air. Air from a compressor is fedfirstly to a pressure regulating valve, from thence to an air filter andfrom thence to a liquid lubricant container. A venturi tube is providedin the liquid lubricant container so that as the air under pressurepasses through said venturi tube the liquid in the container is suckedinto the stream and an atomized mixture of air and liquid then fed to atransfer valve. In the transfer valve the stream of lubricant and air isnormally directed towards an outlet tube where the stream exhausts toatmosphere within a closed container having a port communicating withthe atmosphere, the atomized stream of liquid condenses into liquidwithin the container and the liquid lubricant returns to the lubricantcontainer by gravity or by other means. if however it is desired toprovide a source of air and lubricant adjacent to a needle in a sewingmachine the transfer valve is operated to direct the stream of air andlubricant to the sewing machine and to divert it from the exhaust tube.lDesirably means for operating the transfer valve include aninterconnection with the treadle or stop/start lever or foot operatedswitch of the sewing machine itself, so the interconnecting mechanismmay be arranged so that the transfer valve is opened frictionally intime before the sewing machine motor is operated and similarly thetransfer valve is closed frictionally after the sewing machine motor hasstopped.

By the present invention a jet of air and an atomized jet of liquid isdirected on to the fabric or to the needle of the sewing machineimmediately in the front of the sewing machine and thus immediatelyprior to the needle or needles if a multineedle machine is employed. Thespraying of lubricant on to the needle helps to cool the needle and thusto reduce the possibility of damage caused by a hot needle.

in order that the present invention may be more readily understoodreference is now made to the accompanying drawings in which:

PKG. l is a side view of apparatus according to the present invention,as attached to the sewing machine and table;

FIG. 2 is a more detailed diagram showing the various components of thepresent invention;

FIG. 3 is a detailed perspective view of a presser foot and needle of asewing machine; and

FIG. 4 is a diagrammatic view of the pneumatic circuit for use with thepresent invention.

In the FIGS. a tableconsists of an upright l supporting a horizontalsurface 4 relative to which is supported a sewing machine 2 driven by amotor 6 located beneath the surface 3 through a belt drive 7. The sewingmachine has a needle 3 and a presser foot 31. The needle 3 is reciprocalthrough a needle guide 33. Beneath the surface 4 is a treadle 5 whichoperates the stop/start mechanism 6a for the motor 6. The treadle 5 alsooperates an arm 32 hinged at one end to a bracket 29 which depresses aspring loaded plunger 28 housed in an ON/OFF pneumatic valve 13. Aninlet to the valve 13 is connected to a duct ll.

Referring briefly to FIGS. 2 and 4 a duct 8 is connected to a source ofcompressed air. The duct 8 meets in a T union 9 one part of which isconnected to the duct 10 and the other branch of which connects via aduct 22 to a transfer block 16 having a hand operated ON/OFF switch todisconnect the flow of air into the block. When the switch is open airmay flow through the block to a pressure regulating valve 17 having twooutlets, one of which is connected to a pressure gauge 18 and the otherto a duct 23 connecting with an air filter 15. Different air pressuresare employed according to the nature of the fabric being sewn and thespeed of sewing. The outlet from an air filter 15 connects with a liquidlubricant container is having a venturi tube inside so that as the airpresses through the venturi lubricant located in the container 14 issucked into an airstream and the airstream emerges from the outlet ofcontainer 14 into the duct 24 containing atomized lubricant. Duct 24 isconnected to a transfer valve 19 arranged normally for a direct passagefrom duct 24 connecting to a duct 21 which connects with a reclaimingbottle 20. Normally the atomized lubricant in the airstream emerges froma tube inside bottle 20 and the atomized liquid collects as liquid inthe bottom of said bottle, the air being allowed to exhaust toatmosphere through an appropriate port in the bottle 20. The liquidcollected in the bottom of bottle 20 is returned by gravity via a duct 3to the lubricant container 14. When air is applied to the transfer valveN as for example by operation of the valve 13 duct ll carries compressedair to the transfer valve and switches the connection from inlet duct 2to outlet duct 25 which carries the stream of air and lubricant to anozzle 30 (FIG. 3) which can be adjusted to direct a stream of air andlubricant on to the fabric immediately preceding the entry of the needle3 into said fabric.

Many fabric lubricants have been found to be suitable. Water-basedlubricants for yarns and fabrics may be used but it is throughpreferable to use nonwater-based liquids. The use of water in closeproximity to sewing machine parts and components may in some machinesgive rise to the introduction of rust or tarnishing or alternatively maydissolve some of the conventional lubricant for the machine itself thusreducing the effective working life of the sewing machine. Alternativefabric lubricants are based on vegetable and mineral oils and oneparticularly satisfactory oil is that known as Risella" oil marketed byShell Petroleum Limited.

It has been found that for thicker fabrics an increase in the airpressure is desirable in order to ensure greater penetration of thelubricant into and through the yarns forming the fabric. It is thoughtthat the provision of a fabric lubricant serves the purpose of renderingthe yarns forming the fabric with a slippery upper surface which tendsto deflect a needle as it enters the fabric and thus to reducesubstantially the likelihood of the yarns of the fabric being held whilethe needle pierces said yarns to cut them. The provision of lubricantencourages the needle to slip round and between adjacent yarns formingthe fabric rather than cut into said yarns. Furthermore the deeppenetration of the lubricant forms a liquid surface on the surface ofthe yarns of the fabric and this retards the build up of heat due to thefriction of the needle and the sewing thread being passed through thefabric and thus reduces the likelihood of thermoplastic yarns reaching atemperature of which they are adversely affected. The air jet itselffurther serves to dissipate heat in the needle and adjacent parts andthus to keep cooler those parts of the sewing machine in which heat isgenerated and which in consequence may cause damage to the yarns formingthe fabric.

It has been found that with experiments and using the process accordingto the present invention that substantially higher speeds for the sewingof elastic fabrics is possible. Speeds up to 6,000 stitches per minutehave been found possible without any adverse effect on the fabricitself. In general fabrics whether incorporating rubber-covered threadsor elastomeric yarns are less liable to suffer damage when sewnaccording to the process of the present invention.

1 claim:

1. Apparatus for use with a sewing machine comprising, a fabriclubricant container having an inlet and an outlet, com pressed air meansfor continuously drawing lubricant from said container and deliveringatomized lubricant under pressure through said outlet, a first passagemeans for connecting said outlet to a first nozzle adjacent the sewingmachine needle for spraying a jet of lubricant onto the fabric, areservoir, a second pawage means for connecting said outlet to thereservoir adapted to collect said lubricant in liquid form, and controlmeans connecting said outlet to only one of said passage means at atime, whereby atomized lubricant under pressure is continuouslydelivered from said container, said atomized lubricant being deliveredto either one of said first or second passages in response to theoperation of the control means.

2. Apparatus according to claim 1, wherein said compressed air meansincludes a venturi tube located adjacent to said lubricant container towithdraw lubricant therefrom.

3. Apparatus according to claim 1, including a regulating valve forcontrolling the pressure of the air supplied to said container.

4. Apparatus according to claim 1, wherein said control means includes apneumatically operated valve.

5. Apparatus according to claim 4, including an ON/OFF pneumatic valveand a foot treadle, and wherein said pneumatically operated valve isoperated by the ON/OFF pneumatic valve which is in turn operated by thefoot treadle, said foot treadle connected also to an ON/OFF switch ofthe sewing machine.

6. Apparatus according to claim 1, including means for returning thelubricant which is collected in the reservoir to the lubricantcontainer.

7. Apparatus according to claim 1, wherein said compressed air meanscomprises a compressed air line including, in sequence, a source ofpressurized air, a regulating valve for controlling the pressure of theair subjected to the container, and a passage directing said regulatedcompressed air to the said container.

8. Apparatus according to claim 7, wherein said control means comprisesa pneumatically operated valve, and wherein said air line includes meansfor directing air from said source to said pneumatically operated valveto operate the latter.

9. A method of operating a sewing machine having a sewing needle whichenters and passes through a fabric, comprising the steps of: feeding fa11C to the needle of the sewing machine to sew the fabric, continuouslysupplying a stream of atomized lubricant under pressure through apassageway from a lubricant container to a reservoir, and diverting saidstream from the container at selected times to pass through a nozzleadjacent the sewing machine needle to spray a jet of lubricant onto saidfabric.

10. The method according to claim 9, wherein the step of diverting isperformed to spray the atomized jet of lubricant onto the fabricimmediately before the needle of the sewing machine enters the fabric.

11. The method according to claim 9, wherein the step of continuouslysupplying a stream includes passing compressed air through a lubricantcontainer to form a stream of air containing atomized lubricant andfeeding said stream to a valve having two outlets, one of which isconnected to a nozzle adjacent the sewing machine needle and the otherof which is normally open and is connected to a reservoir and allows thestream to normally pass to the reservoir.

12. A method according to claim 9, including normally returning thelubricant from said reservoir to said lubricant container.

13. The method according to claim 9, including operating a foot treadleof the sewing machine for determining whether the atomized fabriclubricant flows to the reservoir or directly to the nozzle.

14. The method according to claim 9, in which the lubricant is anonwater-based lubricant.

15. The method according to claim 9, wherein the fabric includes elasticyarns, and wherein the lubricant is supplied in an amount sufiicient toprevent overheating of the needle and also to reduce the tendency of theneedle to hold and pierce the elastic yarns.

1. Apparatus for use with a sewing machine comprising, a fabriclubricant container having an inlet and an outlet, compressed air meansfor continuously drawing lubricant from said container and deliveringatomized lubricant under pressure through said outlet, a first passagemeans for connecting said outlet to a first nozzle adjacent the sewingmachine needle for spraying a jet of lubricant onto the fabric, areservoir, a second passage means for connecting said outlet to thereservoir adapted to collect said lubricant in liquid form, and controlmeans connecting said outlet to only one of said passage means at atime, whereby atomized lubricant under pressure is continuouslydelivered from said container, said atomized lubricant being deliveredto either one of said first or sEcond passages in response to theoperation of the control means.
 2. Apparatus according to claim 1,wherein said compressed air means includes a venturi tube locatedadjacent to said lubricant container to withdraw lubricant therefrom. 3.Apparatus according to claim 1, including a regulating valve forcontrolling the pressure of the air supplied to said container. 4.Apparatus according to claim 1, wherein said control means includes apneumatically operated valve.
 5. Apparatus according to claim 4,including an ON/OFF pneumatic valve and a foot treadle, and wherein saidpneumatically operated valve is operated by the ON/OFF pneumatic valvewhich is in turn operated by the foot treadle, said foot treadleconnected also to an ON/OFF switch of the sewing machine.
 6. Apparatusaccording to claim 1, including means for returning the lubricant whichis collected in the reservoir to the lubricant container.
 7. Apparatusaccording to claim 1, wherein said compressed air means comprises acompressed air line including, in sequence, a source of pressurized air,a regulating valve for controlling the pressure of the air subjected tothe container, and a passage directing said regulated compressed air tothe said container.
 8. Apparatus according to claim 7, wherein saidcontrol means comprises a pneumatically operated valve, and wherein saidair line includes means for directing air from said source to saidpneumatically operated valve to operate the latter.
 9. A method ofoperating a sewing machine having a sewing needle which enters andpasses through a fabric, comprising the steps of: feeding fabric to theneedle of the sewing machine to sew the fabric, continuously supplying astream of atomized lubricant under pressure through a passageway from alubricant container to a reservoir, and diverting said stream from thecontainer at selected times to pass through a nozzle adjacent the sewingmachine needle to spray a jet of lubricant onto said fabric.
 10. Themethod according to claim 9, wherein the step of diverting is performedto spray the atomized jet of lubricant onto the fabric immediatelybefore the needle of the sewing machine enters the fabric.
 11. Themethod according to claim 9, wherein the step of continuously supplyinga stream includes passing compressed air through a lubricant containerto form a stream of air containing atomized lubricant and feeding saidstream to a valve having two outlets, one of which is connected to anozzle adjacent the sewing machine needle and the other of which isnormally open and is connected to a reservoir and allows the stream tonormally pass to the reservoir.
 12. A method according to claim 9,including normally returning the lubricant from said reservoir to saidlubricant container.
 13. The method according to claim 9, includingoperating a foot treadle of the sewing machine for determining whetherthe atomized fabric lubricant flows to the reservoir or directly to thenozzle.
 14. The method according to claim 9, in which the lubricant is anonwater-based lubricant.
 15. The method according to claim 9, whereinthe fabric includes elastic yarns, and wherein the lubricant is suppliedin an amount sufficient to prevent overheating of the needle and also toreduce the tendency of the needle to hold and pierce the elastic yarns.